Apparatus for producing concrete blocks and the like



Oct. 25, 1960 L. ZMANlA ETAL APPARATUS FOR PRODUCING CONCRETE BLOCKS ANDTFE LIKE Filed Nov. 23, 1954 6 Sheets-sheaf. 1

4 7 s a 3 w. a MAM m \I myw 2 E4 0 WMC W I 6 ZN A 0 Z 9 MW 5W I. II m Y3 B an ..w a :w 1 if h.. .lhh. 5 1 w \x m w Oct. 25, 1960 L. IZMANIAETAL 2,957,222

APPARATUS FOR PRODUCING CONCRETE BLOCKS AND ma LIKE Filed Nov. 23, 19546 Sheets-Sheet 2 g/vwm F) TTORNE) Oct. 25, v1960 L. ZMANIA EI'AL2,957,222

I APPARATUS FOR PRODUCING CONCRETE BLOCKS AND THE LIKE Filed Nov. 23,1954 V 6 Sheets-Sheet 3 I a v s 49 5/ 5e 66 V l I I I V INVENTORS ATT'ORIVEV Oct. 25, 1960 L. ZMANIA ETAL 2,957,222

APPARATUS FOR PRODUCING CONCRETE BLOCKS AND TPE LIKE Filed Nov. 23, 19546 Sheets-Sheet 4 INVENTORS LEO z my/a MW C O VJEN ATTORNEY Oct. 25, 1960L. ZMANIA arm. 2,957,222-

APPARATUS FOR PRODUCING CONCRETE BLOCKS AND THE LIKE Filed Nov. 23, 1954e Sheets-Sheet 5 FITTOEIUEY Oct. 25, 1960 L. ZMANIA ET AL APPARATUS FORPRODUCING CONCRETE. BLOCKS AND THE LIKE Filed NW3, 1954 OPERATOR 's VBRATOF? l CONTR L SWPL-Q MR IN HTHC 6 Sheets-Sheet 6 wean-ran (AM 331,

MBIN (0H TBCT LIMIT SWITCH B-PHR 5E LINE FFH FH REVERSIBLE Mow-ca 6OUnited States Patent APPARATUS FOR PRODUCING CONCRETE BLOCKS AND THELIKE Leo Zmania, 4611 W. 87th Place, Oak Lawn, IlL, and Marvin C. Onsen,1226 Circle Ave., Forest Park, Ill.

Filed Nov. 23, 1954, Ser. No. 470,661

'6 Claims. (CI. 25-41) This invention relates generally to blockmanufacturing and more particularly is concerned with improved means formanufacturing concrete building blocks which are uniform in size anddensity.

The necessity for height and density control in the manufacture ofconcrete blocks is unquestioned, since uniform blocks stack better inthe yard and please the mason who wants to lay straight courses with aneven mortar line. One known method of producing uniform blocks is tofill the block forming mold with an ample charge of concrete and to thenvibrate the same for a period of time just sufficient to compact theconcrete to a predetermined height. This method is not entirelysatisfactory because the charge of concrete may be such in quantity andcondition that it cannot be reduced to the predetermined height byvibration, as a consequence of which the machine must be stopped untilthe condition is corrected. Another known method of producing uniformblocks is to fit the block making machine with a cut-off bar operativeto afford charges of concrete uniform in quantity. This latter methodalso is not entirely satisfactory because when the condition of theconcrete in the supply hopper changes, the cut-off bar must be adjustedto correspond, and the required adjustment cannot be made until themachine is stopped.

Accordingly, a principal object of the present invention is to provide aconcrete building block machine with improved height and density controlmeans which functions automatically and without any necessity forstopping the machine.

Another object of the present invention is to provide such a devicewhich can adjust for each block forming cycle and which is operative toreduce a concrete charge in a mold of predetermined cross sectional areato an uncompacted height dependent upon the condition of the concretecharge from which the last block was made.

Still another object of the present invention is to provide such adevice which adjusts as aforementioned to effectively control theoperating level of means for wiping across the top of the mold to affordan uncompacted charge of concrete the height of which bears a criticalrelation to the condition of the concrete charge from which the lastblock was made.

And a further object of the present invention is to provide a concretebuilding block machine which nor mally is operative to terminate thecompacting operation when the concrete in the mold is finally reduced toa predetermined height, without regard to the point in the block makingcycle when the concrete may be reduced to such height.

And still another object of the present invention is to provide such adevice which is exceedingly simple in design and construction and whichis comparatively simple and inexpensive to manufacture.

Other objects and advantages of the present invention will appear morefully hereinafter, it being understood that said invention consistssubstantially in the combination, construction, location and generalarrangement of "ice parts, all as described in detail in the followingspecification, as shown in the accompanying drawings and as fullypointed out in the appended claims.

In the accompanying drawings:

Figure 1 is a perspective view looking at the front and the right sideof a block forming machine embodying the present invention;

Figure 2 is a perspective view looking at the front and the right sideof the machine and showing the main frame mold section and the feed boxassembly, a portion of the stripper frame assembly and the controldevice;

Figure 3 is a vertical section taken on line 3--3 of Figure 1;

Figure 4 is an enlarged vertical section through a portion of themachine, the feed box assembly being shown in its retracted position andfully elevated;

Figure 5 is the same as Figure 4, however, the feed box assembly isshown in its forwardly extended position and only partially elevated;

Figure 6 is the same as Figure 4, however, the feed box is shown fullylowered;

Figure 7 is a vertical longitudinal section through the machine, thefeed box being shown in its retracted 'position and fully lowered, andthe stripper head being shown fully :lowered for stripping the mold anddelivering the finished block to the pallet receiver frame assembly;

Figure 8 is an enlarged vertical section on line 8-8 of Figure 3;

Figure 9 is an elevation of the machine as viewed from the left side,just prior to descent of the stripper head;

Figure 10 is a fragmentary elevation of the machine as viewed from theleft side, just prior to ascent of the stripper head; and

Figure 11 is a wiring diagram schematically showing the main controlelectric circuit for controlling the action of the height and densitycontrol device of the present invention.

It will be understood that the present invention comprises means forautomatically producing concrete building blocks of predeterminedlyestablished uniform height and density without necessitating anysubstantial interruption in the operation of the block-making machine.Inasmuch as the block-making machine in which is incorporated thepresent invention is of conventional construction and well known in theart, only such parts of the machine as are necessary for a clearunderstanding of the present invention have been shown in the drawingsand will be described in the following specification.

Now referring to the drawings, the machine embodying the presentinvention comprises a floor supported main frame indicated generally bythe numeral 10. The main frame 10 includes a mold section 11 located asuitable distance above the floor. Operatively mounted upon the mainframe 10 at an elevation just above that of the mold 11 is a feed boxassembly indicated generally by the numeral 12. Directly over the mold11 is a stripper head assembly indicated generally by the numeral 13,and directly under the mold 11 is a pallet receiver assembly indicatedgenerally by the numeral 14.

Suitable power transmitting means is provided for actuating the feederbox assembly 12, stripper head assembly 13 and pallet receiver assembly14 in a predetermined timed relation. The aforementioned means includesan electric motor 15 located on the right side and to the rear of themachine. The motor 15 is provided with a belt 15 through which it drivesa jack shaft 16, and the latter is provided with a second belt 16located laterally outwardly of the belt 15*, through which it drives apulley shaft 17. On the left side of the machine, the pulley shaft 17 isprovided with a spur pinion 17 which drives a spur gear 17 and a camshaft 18 upon which the spur gear 17 is mounted.

., V l a 3" In addition to mounting the spur gear 17 the cam shaft 18mounts a feed box control cam 18 located laterally outwardly of the spurgear 17*. On the right side ofjhe machine, the'cam shaft 18 mounts apair of stripper head; control {cams 19 and 19 and a pallet receivercontrol cam 20 located laterally outwardly of the cams 19 and 19 Thefeed box control cam 18 engages a cam follower arm 20* which is mountedupon a feeder arm shaft 21. In addition to mounting the cam follower arm20*, the feeder arm shaft 21 mounts a pair of feeder arms 21*---21located respectively on opposite sides of the machine and operativelyconnected to the feed box assembly 12 through the medium of a pair ofrods 22-22. For maintaining the cam follower arm 20 engaged with thefeed box control. cam 18 a suitable tension spring assembly 23 isoperatively interposed between the feeder arm shaft 21'and a beam 24which is anchored to the main frame 10 of the machine. The stripper headcontrol earns 19 and 19 respectively engage a pair of cam follower arms25 and 25 which are mounted upon a stripper head shaft 26. 'In additionto mounting the cam follower arms 25 and 25 the stripper head shaft 26mounts a pair of rock arms 27-27 located respectively on opposite sidesof the machine and operatively connected .tothe stripper head assembly13 'through the medium of a pair of links 28-28. The pallet receivercontrol eam'zo engages a cam follower arm 28* which is mounted upon apallet receiver shaft 29. In addition to mounting the cam follower arm128*, the pallet receiver shaft 29 mounts a pair of rock arms 30-30located respectively on opposite sides of the machine and operativelyconnected to the pallet receiver assembly 14 through the medium ofcompression spring link assemblies 31-31.

Referring particularly to Figure 3, in the operation of the machine, afeed box 31 which is included in the feed box assembly 12, is chargedwith wet concrete from an overhead supply hopper 32. The feed box 31then moves to the forwardly extended position shown in Figure to locatethe charge of wet concrete over the mold The charge immediately dropsinto the mold 11, and then the feed box 31 retracts to its originalposition under the hopper 32. For compacting the fresh concrete withwhich the mold 11 is charged, vibrator assembiles indicated generally bythe numerals 33-33 are provided. The vibrators 33-33 are connected inelectric circuit with a vibrator cam switch 33* which is operatedby a'vibrator cam 33 mounted on the cam shaft 18 and located laterallyoutwardly of the feed box control cam 18*. The vibrator cam 33*" is ofsuch shape and is so mounted that thes'witch 33 is depressed for apredetermined portion of the block making cycle of the machine,commencing whenthe feed box 31 begins to move forwardly to deliver itscharge. to' the mold 11-, vibration of the latter being effected therebyfor a corresponding portion of the aforementioned cycle. After the feedbox 31 has delivered its charge and returned to its original positionunder the hopper 32, a stripper head 34, which 'is included in thestripper head assembly 13, descends to finally compact the block to itsrequired height and to thereafter stripthe completed block 34 from themold 11. The block 34 and a supporting pallet 35, which is included inthe pallet receiver assembly 14, are then lowered to the position shownin Figure 7, from which position the completed block 34* is free to beremoved from the machine either by hand orany suitable power-operatedmeans. During the actual stripping op eration, the stripper head 34 andthe pallet 35 move downwardly'together normally 'at a distance apartcorresponding to the desired height of'the block 34*. This distance 'iscontrolled by a pairof. adjustable spacer members carried by thestripperhead assembly for movement therewith and a pair of spacer members whichregister respectively with the aforementioned adjustable spacer membersand which are carried by the palle recei e a se r 4 movement therewith,there being one pair of registering spacer members on each sideof themachine. In the block making machine of the character just described,when the concrete mix is too fluid for formation of a block of therequired density, the tendency is for the block to be compacted to itsrequired height before the vibration period terminates, in consequenceof which the vibration which occurs subsequent to compacting of theblock 34 to its required height further compacts the concrete, thuscausing the formation of a block which is of a height less than thatdesired. .On the other hand, when the concrete mix is too firm forformation of a block'of the required density, the tendencyis for thevibration period to terminate before the block is compacted to the desired height, which, of course, is undesirable. In addition, the pallet35 may begin to move downwardly before the stripper head 34 hassufficient time to compact the concrete in the mold 11 to the desiredheight, inconsequence of which there may be formed a block which is of aheight greater than that desired. The construction and operation of themachine as so far described is old and well known in the art, and,therefore, any further general description is deemed to be unnecessaryfor a full understanding of the present invention.

'The feed box 31 conventionally includes a pair of transversely spacedside plates 36-36 the corresponding rear end portions of which arejoined by a bar '37 and corresponding intermediate portions of which arejoined by a bar 38 and additionally by a plate 39 positioned as shown.Corresponding front end portions of the side plates 36-36 respectivelymount angle brackets 42-42 and rollers 43-43. The corresponding frontterminal portions of the side plates 36-36 are joined by a rigid cut-offbar 44 which is removably secured in any suitable manner againstdisplacement and for movement with the feed box 31*. The feed boxassembly 12, including the feed box 31 just described, is normallymounted in the conventional machine on the main frame 10 for simplerectilinear movement of the feed box 31 fore and aft of the machine. Inorder to adapt the machine to and for the purposes of the presentinvention, the feed box assembly 12 is mounted on the main frame 10. ina different manner now to be described.

For operatively supporting the front end of the feed box 31*, the feedbox assembly 12 includes a track subassembly 45 having laterally spacedparallel tracks 46-46 located respectively on opposite sides of the feedbox 31* and in underlying relation to the rollers 43-43. The front endportions of the tracks 46-46 are fitted respectively with a pair of pins47-47 through the medium of which the fore ends of the tracks aresupported respectively by a pair of levers 48-48 which are to bedescribed hereinafter. Corresponding rear end portions of the tracks46-46 are secured respectively to opposite side front end portions of anapron plate 49, as by spaces 50-50 and bolts 51. The opposite side rearend portions of the apron plate 49 are fitted respectively with a pairof brackets 52-52 which are respectively pivoted on a pair of studs 52-52 The latter are coaxially related and project inwardly respectivelyfrom opposite sides of the main frame 10 and respectively through thebrackets 52-52, the subassembly 45 being thereby mounted on the mainframe 10 for pivotal movement about a transversely extending horizontalaxis.

For operatively supporting the rear end of the feed box 31*, the feed'box 31 is provided with a longitudinally extending runner plate 52 thefront end of which is secured to the underside of the plate 39 and therear end of which is proximate thebar 37. Underlying the runner plate 52is a roller 52 carried by a cross beam 52 anchored to the main frame 10.The feed box 31 isthus adapted to reciprocate'fore and aft over theroller 52 and additionally to rock thereon when the front end of-thefeeder box 31 is raised or lowered in the manner to be describedhereinafter.

The height and density control device of the present invention comprisesa rock shaft 53 which is journaled in corresponding opposite sideportions of the main frame 10, as at 54-54, and which is provided with apair of rock arms 55-55 pivotally connected respectively to the lowerends of a pair of link assemblies 56-56. The upper ends of the linkassemblies 56-56 are pivotally connected respectively to correspondingends of the pair of levers 48-48. The levers 48-48 extend forwardly fromthe link assemblies 56-56 respectively in superposed spaced relation tothe rock arms 55-55. The front end portions of the levers are suitablyshaped to provide elements 57-57 respectively for seating the pins47-47'. A pair of brackets 58-58 project inwardly from correspondingopposite side portions of the main frame and are disposed respectivelyin underlying relation to corresponding intermediate portions of thelevers 48-48 for rocking movement of the levers 48-48 thereon inresponse to oscillating movement of the shaft 53. For actuating thelatter, the same is coupled to a speed reduction unit 59 which derivespower from a reversible three phase electric motor 60 through a beltdrive 61. The action of the height and density control device of thepresent invention is determined by rotation of the reversible motor 60,and the motor 60, in turn, is controlled by apparatus connected in amain control electric circuit hereinafter described.

As set forth hereinbefore, the feed box 31 retracts to its originalposition under the hopper 32 after dropping a charge of fresh concreteinto the mold 11. As the feed box retracts, the cut-off bar 44 wipesacross the top of the fresh concrete and removes any excess materialwhich extends above the lower edge of the cutoff bar 44. Then thestripper head 34 descends and normally rests upon the concrete, floatingfree of the stripper head control cam 19- for the short period of time(just prior to commencement of the actual stripping operation) duringwhich the block 34 is compacted to the required height. When theconcrete mix is properly proportioned for the production of blocks ofthe desired height and density the spacer members carried respectivelyby the stripper head and pallet receiver assemblies make contact at apredetermined point during the block making cycle. The time when thespacer members make contact may be advanced or delayed, depending uponthe condition of the concrete mix. The concrete mix may be too fluid orsoft, in which event it may not support the stripper head 34 at all, or,if it does, the period of time during which the stripper head 34 restson and is supported by the concrete is cut short, in consequence ofwhich the time when the spacer members make contact is advanced. On theother hand, the concrete mix may be too stiff or firm, in which eventthe aforementioned period of time is extended, in consequence of whichthe time when the spacer members make contact is delayed.

When the concrete mix is too fluid or soft and the spacer members makecontact prematurely, as aforementioned, a block of the desired height isformed, provided there was enough concrete to adequately fill the mold11, but the block is of lesser density then that desired, in consequenceof which adjustment of the machine is required. The necessary adjustmentis effected automatically by the height and density control mechanism ofthe present invention as follows. The rotation of the electric motor 60is translated into counter clockwise movement of the rock shaft 53 andof the rock arms 55-55 (as viewed from the left side of the machine), inconsequence of which the link assemblies 56-56 are drawn downwardly andthe levers 48-48 are rocked respectively on the brackets 58-58 in acounter clockwise direction so as to raise the front ends of the tracks46-46 through the medium of the pins 47-47 (see Figure 6 and comparewith Figures 4 and 5). Since the front end of the feed box 31*- iscarried by the tracks 46-46, it is raised correspondingly, inconsequence of which the cut-off bar 44 is adjusted for operation at ahigher level.

When the concrete mix is too stifi or firm and the spacer members makedelayed contact, as aforementioned, a block of greater density and/orheight is formed, in consequence of which adjustment of the machine isrequired. The necessary adjustment is effected automatically by theheight and-density control mechanism of the present invention asfollows. The rotation of the electric motor 60 is translated intoclockwise movement of the rock shaft 53 and of the rock arms 55-55 (asviewed from the left side of the machine) as a consequence of which thelink assemblies 56-56 shift upwardly and levers 48-48 are rockedrespectively on the brackets 58-58 in a clockwise direction so as tolower the fore ends of the tracks 46-46 through the medium of the pins47-47 (see Figure 4 and compare with Figures 5 and 6). Since the frontend of the feed box 31 is carried by the tracks 46-46, it is loweredcorrespondingly, in consequence of which the cut-off bar 44 is adjustedfor operation at a lower level.

The height and density control device of the present invention adjustsnot more than once during each block making cycle. Each adjustmentraises or lowers the cutoff bar a uniform selected distance, inconsequence of which it may require a number of successive adjustmentsto raise or lower the cut-off bar to the best operating position.

Referring particularly to Figure 11, the main control circuit includesthe vibrator cam switch 33 The latter is operated by the vibrator cam33*, which is operatively connected to the electric motor 15 forrotation thereby at a rate which is uniform. The electric motor 15 isconventionally connected in an electric circuit which is not describedor shown herein. In addition to the vibrator cam switch 33 the maincontrol circuit includes a pair of main contacts 65 and 66. The maincontact 65 is the spacer member on the left side of the machine,mentioned hereinbefore, carried by the stripper head assembly 13, andthe main contact 66 is a cap mounted upon and suitably insulated fromthe underlying registering spacer member carried by the pallet receiverassembly 14.

The main control circuit also includes a mercury switch which has a lefthand set and a right hand set of contaots, and which is arranged foroperation when it is suitably shorted. In addition to the mercuryswitch, the main control circuit includes an operators vibrator controlswitch through the medium of which operation of the vibrators 33-33 maybe terminated and through which automatic or manual operation of thevibrators 33-33 may be selectively effected.

The relay designated R1 is an automatic circuit control relay whichcontrols the vibrators 33-33. Whenever the relay R1 is energized, thevibrators operate; whenever the relay R1 is dc-energized, the vibratorsare disabled. The timer designated Tl. is a lowering circuit timer whichis set up when a safety circuit relay designated R2 is energized. Inaddition to setting up the timer T1, the relay R2, at the same time,operates the mercury switch. The timer designated T2 is a naisingcircuit timer, and the timer designated T3 is operative to preventexcessively sensitive operation of the timer T2. The relay designated R3is a raise relay which, when energized, closes a switch S3 in the3-phase power line for reversible motor 69, in consequence of which themotor 60 rotates in a direction which effects raising of the cut-off bar44 in the manner already described. The relay designated, R4- is alowering relay which, when energized, closes a switch S4 in the 3-phasepower line for reversible motor- 64), in consequence of which the motor60 rotates in a direction which effects lowering of the cut-off bar 44in" the manner already described. The relay designated R5 is operativeto control the point in the block making cycle blocks to be made.

7 at which the raising operation begins. .For limiting lowering of thecut-01f bar 44, a limit switch 62 is furnished, and ,for limitingelevation of the cut-01f bar 44, a limit switch 63 is furnished. Thelimit switches 62 and 63 are suitably disposed for coaction with aswitch actuating arm 64 which is carried by the link assembly 56lo'cated 'on the left side of the machine.

; During the initial portion of each block making cycle, i.e., while thevibrator cam switch 33 is engaged with the leading portion of the raisedpart of the vibrator cam 33', and themain contacts 65 and 66 aredisengaged, the vibrator cam switch 33 is in the full line depressedposition shown in the wiring diagram, and the mercury switch is in itsuuoperated position, wherein the left hand seto' f contacts are closedand the right hand set of contacts are open. In this condition of themain circuit, electric current is supplied to the relay R1 and the timerT3 through the operators switch and the vibrator cam switch 33 theclosed. left hand, contacts of the mercury switch and the closedcontacts R1 of the relay R1. Since relay R1 is energized, the vibratorsoperate. In addition, the normally open co'ntacts R1 and R1-1 of therelay R1 are closed, while the normally closed contacts R1-2 of'therelay R1 are open. Since the timer T3 is energized, the normally closedtime closed contacts T3 of the timer T3 are open. The vibrator camswitch 33 cuts off the supply of electric current to the relay R2, inconsequence of which the normally open contacts R2 and R2-1 of relay R2are open. Since the contacts R2 are open, the supply of current to thetimer T1 is cut off, as a result of which the normally open timed opencontacts .T1 of the timer T1 are open. The supply of current to therelay R4 is cut 01f by the open contacts RI-Z of the relay R1 and T1 ofthe timer T1. The open right hand setof contacts of the mercury switchand the open contacts T3 of the timer T3 cut 011 the supply of electriccurrent to the relay R5 and the timer T2, in consequence of which thenormally closed contacts R5 of therelay R5 are closed, and the normallyopen timed open contacts T2 of the timer T2 are open, cutting off thesupply of electric current to the relay R3. Since the electric currentis cut off from both the raise relay R3 and the lowering relay R4,neither the switch S3 nor the switch S4is operated, in consequence ofwhich the reversible motor 60 remains motionless.

In initially arrangingthe machine for operation, the spacer members areadjusted so that when they engage, the stripper head 34 and the pallet35 are a clear distance apart corresponding to the desired height of theIn addition, the vibrator cam 33 (a compound adjustable member) isadjusted so that when the concrete mix is properly proportioned for theformation of a block of the desired height and density,

the vibrator cam switch 33* is depressed when the block forming cyclebegins and is released as the main contacts 65 and 66 engage.

Again referring particularly to Figure 11, when the machine is initiallyarranged as aforementioned and a properly proportioned concrete mix isutilized, upon simultaneous release of the vibrator cam switch 33 andengagement of the main contacts 65 and 66, the vibrator cam switch 33assumes the dotted line released position shown in the wiring diagram,and the mercury switch is operated so that the left hand set of contactsopen and the right hand contacts close. In this condition of the maincontrol circuit, the electric current is cut off from the relay R1 andthe timer T3 by the vibnato'r cam switch 33 the open left hand set ofcontacts of the mercury switch and the open contacts R1 of the relay R1.Since the relay R1 is de-energized, the vibrators cease to operate. Inaddition, the normally open contacts.R1 and R11 of the relay R1 open,while the normally closed contacts R1-2 of the relay R1 close. Thenormally closed time clo'sed contacts T3 of the timer "T3 remain open.The supply of electric current tothe relay R2 is cut ofi by the opencontacts R1-1- of the relay R1, in consequence of which the normallyopen contacts R2 of the relay R2 remain open, cutting off the supply ofelectric current to the timer T1. In turn, thenormally open timed opencontacts T1 of the timer T1 remain open, cutting ofi the supply ofelectric current to the relay R4. The vibrator cam switch 3-3 and theopen contacts T3 of the timer T3 and R1 of the relay R1cut ofi thesupply of electric current to the relay R5 and the timer T2, inconsequence of which the normally closed contacts R5 or" the relay R5remain closed, and the no'rmally open timed open contacts T2 of thetimer T2 remain open, cutting oil. the supply of electric current to therelay R3. Since the electric current remains cut oil. from both theraise relay R3 and the lowering relay R4, neither the switch S3 nor theswitch S4 is operated, in consequence of which the reversible motor 61still remains motionless.

When the concrete mix is too fluid or soft and the main contacts 65 and66 make'contact prematurely, i.e., before the vibrator camswitch 33 isreleased by the vibrator cam 33", the vibrator cam switch remains in thefull line depressed position shown in'the wiring diagram, and themercury switch is operated so that the left hand set of contacts openand the right hand set of cont-acts close. In this condition of the maincontrol circuit the electric current is cut ofi from the relay R1 andthe timer T3 by the open left hand set of contacts of the mercury switchand the open contacts R1 of the relay R1. Since the relay R1 istie-energized, the vibrators cease to operate. In addition, the normallyopen contacts R1 and R1.-1 of the relay R1 open, while the normallyclosed contacts R1-2 of the relay R1 close. The normally closed timeclosed contacts T3 of the timer T3 remain open. The supply of electriccurrent to the relay R2 is cut ofi by the vibrator cam switch 33 and theopen contacts Rl-l of the relay R1, in consequence of which the normallyopen contacts R2 of the relay R2 remain open. The supply'of electriccurrent to the timer T1 is cut oiT by the vibrator cam switch 33 and theopen contacts R2 of the relay R2. The normally open til-ned opencontacts T1 of the timer T1 remain open, cutting off the supply ofcurrent to the relay R4. The open contacts T3 of the timer T3 cut offthe supply of electric current to the relay R5 and the timer T2, inconsequence of which the normally closed contacts R5 remain closed, andthe normally open timed open contacts T2 of the timer T2 remain open,cutting 011 the supply of electric current to the relay R3. Since theelectric current remains cut off from both the raise relay R3 and thelowering relay R4, neither the switch S3 nor the switch S4 is operated,in consequence of which the reversible motor 60 continues motionless.

After a predetermined time interval, the normally closed time closedcontacts T3 of the timer T3 close, whereupon electric current issupplied to the relay R5 and the timer T2 through the operators switchand the vibrator cam switch 33 the closed left hand set of contacts ofthe mercury switch and the closed contacts T3 of the timer T3. Since thetimer T2 is energized, the normally open timed open contacts T2 of thetimer T2 close, and since the relay R5 is energized, the normally closedcontacts R5 of the relay R5 open, cutting off the supply of current tothe relay R3.

When the vibrator cam switch 33 is finally released by the vibrator cam33', the electric current to the relay R5 and the timer T2 is cut off bythe vibrator cam switch 33 and the open contacts R1 of the relay R1, therelay R5 and timer T2 being de-energized simultaneously. Since the relayR5 is de-energized the normally closed contacts R5 of the relay R5close. The normally open timed open contacts T2 of the timer T2 remainclosed, whereupon electric current is supplied to the raise relay R3 isclosed and the reversible motor 60 is supplied with electric current forrotation thereof in a direction to raise the cut-off bar 44. After apredetermined interval, the contacts T2 of the timer T2 open and thesupply of electric current to the raise relay R3 is cut ofi, whereuponthe switch S3 opens and the supply of electric current to the reversiblemotor 60 is cut oflf.

When the concrete mix is too stiff or firm and the vibrator cam switch33- is released while the main contacts 65 and 66 are still separated,the vibrator cam switch 33 assumes the dotted line released positionshown inthe wiring diagram, and the mercury switch initially remains inthe unoperated position, wherein the left hand set of contacts areclosed and the right hand set of contacts are open. In this condition ofthe main control circuit, electric current is supplied to the relay R1and the timer T3 through the closed contacts R1 of the relay R1 and theclosed left hand set of contacts of the mercury switch. Since the relayR1 is energized, the vibrators continue to operate. In addition, thenormally open contacts R1-1 of the relay R1 remain closed and thenormally closed contacts R1-2 of the relay R1 remain open. The normallyclosed time closed contacts T3 of the timer T3 remain open. The relay R2is supplied with electric current through the vibrator camswitch and theclosed contacts R1-1 of the relay R1, in consequence of which thenormally open contacts R2 of the relay R2 close, whereupon electriccurrent is supplied to the timer T1 through the vibrator switch and theclosed contacts R2. Since the timer T1 is energized, the normally opentimed open contacts T1 of the timer T1 close. The supply of electriccurrent to relay R5 and timer T2 remains cut oii by the open left handcontacts of the mercury switch and the open contacts T3 of the timer T3,in consequence of which the normally closed contacts R5 of the relay R5remain closed, and the normally open timed open contacts T2 of the timerT2 remain open. The supply of electric current to the relays R3 and R4is cut ofi respectively by the open contacts T2 of the timer T2 and R1-2of the relay R1.

When the relay R2 is energized as aforementioned, in addition to thenormally open contacts R2 of the relay R2 being closed, the normallyopen contacts R21 of the relay R2 are closed, in consequence of whichthe mercury switch is operated, the left hand contacts being opened.

and the right hand contacts being closed. It will be understood thatthere is a slight time delay between release of the vibrator cam switch33 and operation of the mercury switch In this condition of the maincontrol circuit, the supp-1y of electric current is cut off from therelay R1 and the timer T3 by the vibrator cam switch 33 and the openleft hand contacts of the mercury switch. Since the relay R1 isde-energized, the vibrators cease to operate. In addition, the normallyopen contacts R1 and R1-1 of the relay R1 open, and the normally closedcontacts R12 of the relay R1 close. The normally closed time closedcontacts T3 of the timer T3 remain open. The supply of electric currentto the relay R5 and the timer T2 is cut off by the open contacts R1 ofthe relay R1 and T3 of the timer T3 and by the vibrator cam switch. Therelay R5 being de-energized, the normally closed contacts R5 of therelay R5 remain closed, and the timer T2 being de-energized, thenormally open timed open contacts T2 remain open, cutting ofi the supplyof electric current to the relay R3. The supply of electric current iscut off from the relay R2 by the open contacts R14. Since the relay R2is de-energized, the contacts R2 of the relay R2 open, cutting ofi thesupply of electric current to timer T1. The normally open timed opencontacts T1 of the timer T1 remain closed, whereupon elec tric currentis supplied to the lowering relay R4 through the closed contacts R12 ofthe relay R1 and T1 of the timer T1, in consequence of which the relayR4 operates the switch S4, closing the same to supply the reversiblemotor 60 with electric current for rotation thereof in a direction tolower the cut-ofi bar 44. After a predetermined interval, the contactsT1 of the timer T1 open and the supply of electric current to thelowering relay R4 is cut off, whereupon the switch S4 opens and thesupply of electric current to the reversible motor 60 is cut oflE.

It will be understood, of course, that the present invention issusceptible of various changm and modifications which may be made fromtime to time without involving any departure from the general principlesor real spirit thereof. For example, instead of the mold beingpositionally fixed and the cut-oif bar movable thereover, the cut-oifbar might be positionally fixed and the mold movable thereunder.Accordingly, it is intended to claim the same broadly, as well asspecifically, as indicated in the appended claims.

What is claimed as new and useful is:

1. In a block making machine which operates automatically in repeatingblock making cycles having a mold, means for charging said mold with adetermined volume of block molding material, and means for compactingthe material in said mold to form a block and for stripping the blockfrom said mold; the combination comprising a pair of laterally spacedparallel rails respectively disposed at opposite sides of the mold andextending fore and aft of the machine, a bottomless feed box movablyalong said rails and having a front wall the bottom edge portion ofwhich is adapted to scrape the upper surface of moldable materialdeposited in the mold by said feed box, pivot means associated with saidrails and spaced rearwardly of the mold for permitting tilting movementof the rails relatively to the horizontal and corresponding variation inspacing of the front wall of the feed box above the mold, meansoperatively connected to the rails proximate their fore ends to tilt therails about said pivot and thereby vary the inclination of said feed boxin accordance with the tilt of said rails, said rail tilting membersextending upwardly from below the rails toward said fore ends of therails, and means underlying said rails for supporting said rail-tiltingmembers.

2. In a block making machine which operates automatically in repeatingblock making cycles having a mold, means for charging said mold with adetermined volume of block molding material, and means for compactingthe material in said mold to form a block and for stripping the blockfrom said mold; the combination comprising a pair of laterally spacedparallel rails respectively disposed at opposite sides of the mold andextending fore and aft of the machine, a bottomless feed box movablealong said rails and having a front wall the botom edge of which isadapted to scrape the upper surface of moldable material deposited inthe mold by said feed box, pivot means associated with said rails andspaced rearwardly of the mold for permitting tilting movement of therails relatively to the horizontal and corresponding variation inelevation of the front wall of the feed box above the mold, and meansoperatively connected to the rails proximate their fore ends to tilt therails about said pivot and thereby vary the inclination of said feed boxin accordance with the tilt of said rails, said last-mentioned meansincluding a pair of levers extending fore and aft of the machine andrespectively fulcrumed for tilting movement about relatively stationarysupports located beneath the rails and immediately to the rear of thepoints of connection of said levers to said rails.

3. In a block making machine which operates automatically in repeatingblock making cycles having a mold, means for charging said mold with adetermined volume of block molding material, and means for compactingthe material in said mold to form a block and for stripping the blockfrom said mold; the combination comprising a pair of laterally spacedparallel rails respectively disposed at opposite sides of the mold andextending fore and aft of the machine, a bottomless feed box having afront wall the bottom edge portion of which is adapted to scrapetheupper surface of moldable material deposited in the mold by said feedbox, pivot means associated with said rails and spaced rearwardly of themold for permitting tilting movement of the rails relatively to thehorizontal and corresponding variation in elevation of the front wall ofthe feed box above the mold, and means operatively connected to therails proximate their fore ends to tilt the rails about said pivot andthereby vary the inclination of said feed box in accordance with thetilt of said rails, said last-mentioned means comprising a lever systemincluding a pair of levers respectively disposed adjacent the outersides of said rails in underlying relation to said feed box, stationaryfulcrum elements for said levers respectively disposed beneath the railsadjacent-the fore ends thereof and reversible motor driven means forcommonly raising or lowering the rear ends of said levers toc'orrespondingly shift'the same about their fulcrum elements and so varythe inclination of said rails.

' '4. In a block making machine which operates automatically inrepeating block making cycles having a mold, means for charging saidmold with a determined volume of block moldingmaterial, and meansfor'comp acting the material in said mold to form a block and forstripping the block from said mold; the combination comprising a pair oflaterally spaced parallel rails respectively disposed at opposite sidesof the mold and extending fore and aft of the machine, a bottomless feedbox movable along saidrails and having a front wall the bottom edgeportion of which is adapted to scrap the upper surface of moldablematerial deposited in the mold leg said feed box, pivot means associatedwith said rails and spaced rearwardly of the mold for permitting tiltingmovement of' the rails relatively to the horizontal and correspondingvariation in spacing of the front wall of the feed box above the mold,means operatively connected to the rails proximate their fore ends totilt'the rails about said pivot and thereby vary the inclination of saidfeed box in accordance with the tilt of said rails, said last-mentionedmeans including a pair of rail-lifting members respectively disposed toeither side of and below the plane of travel of the feed box andreversible power driven means commonly operative upon said lever membersto tilt said rails, said power means being located below said feed boxrearwardly of the mold box.

5. In combination, an open-topped bottomless feed box 12 for blockmolding machines for supplying the mold thereof with a determined volumeof block molding material, said feed box having at its front end asa'fixed part thereof a cut-off bar'of a length suflicient totransversely r span; the mold, a stationary apron plate underlying andnormally closing the bottom of said feed box, a pair of laterally spacedrails extending rearwardly from opposite "sides of said mold along whichsaid feed box is adapted to travel during its reciprocation between abox-filling station and 'a mold charging station over the mold, pivotmeans associated with said rails and spaced rearwardly of the mold forpermitting tilting movement of the rails relatively to the horizontaland corresponding variations 7 in elevation of the feed box cut-'ofl barabove the mold,

and means operatively connected to the rails proximate their fore endsto tilt the rails about said pivot and thereby vary the inclination ofsaid feed box in accordance with the tilt of said rails, saidlast-mentioned means comprising a lever system including a pair oflevers respectively disposed adjacent the outer sides of said rails inunderlying relation to said feed box, stationary fulcrum elements forsaid levers respectively disposed beneath the rails adjacent the foreends thereof and reversible motor driven means for commonly raising orlowering the rear ends of said levers to correspondingly shift the sameabout their fulcrum elements and so vary the inclination of said rails.

6. In the combination as defined in claim 4 wherein said reversiblemotor driven means is also disposed in underlying relation to the feedbox.

References Cited in the file of this patent UNITED STATES PATENTS

